Instance Method


Tells the delegate when the app has finished launching. Don’t use. Instead, use application(_:didFinishLaunchingWithOptions:).


optional func applicationDidFinishLaunching(_ application: UIApplication)



The singleton app object.


Although not formally deprecated, do not use this method in your apps. Use the application(_:willFinishLaunchingWithOptions:) and application(_:didFinishLaunchingWithOptions:) methods instead.

Your implementation of this method should create your app’s user interface and initialize the app’s data structures. If your app persists its state between launches, you would also use this method to restore your app to its previous state.

After calling this method, the app also posts a didFinishLaunchingNotification notification to give interested objects a chance to respond to the initialization cycle.

See Also

Initializing the App

func application(UIApplication, willFinishLaunchingWithOptions: [UIApplication.LaunchOptionsKey : Any]?) -> Bool

Tells the delegate that the launch process has begun but that state restoration has not yet occurred.

func application(UIApplication, didFinishLaunchingWithOptions: [UIApplication.LaunchOptionsKey : Any]?) -> Bool

Tells the delegate that the launch process is almost done and the app is almost ready to run.

struct UIApplication.LaunchOptionsKey

Keys used to access values in the launch options dictionary passed to your app at initialization time.

class let didFinishLaunchingNotification: NSNotification.Name

Posted immediately after the app finishes launching.